Isolation and identification of pathogenic Escherichia coli from pheasant
In order to investigate the cause of mass deaths in a pheasant farm in Qinhuangdao City,the isolated dominant pathogenic strains were subjected to biochemical identification and 16S rRNA gene sequence analysis.Additionally,the sensitivity of the isolated bacteria to 21 antibiotics was tested,and PCR was employed to detect antibiotic resistance genes.Pathogenicity tests were conducted using clean Kunming mice and SPF chicken embryos,and PCR was used to detect virulence genes of the isolated bacteria.The results revealed that the isolated bacteria were Gram-negative rods,forming colonies with a metallic sheen on eosin methylene blue agar,and their biochemical characteristics matched those of Escherichia coli with a high agreement rate of 99%.BLAST analysis indicated a 99.8%similarity between the 16S rRNA sequence of the isolated bacteria and that of Escherichia coli.The isolated bacteria exhibited high sensitivity to enrofloxacin and amikacin but resistance to 15 other drugs,including penicillin and ceftriaxone.The resistance genes of the isolated bacteria related to sulfonamides,β-lactams,and tetracyclines were consistent with the resistance phenotype,while other resistance genes did not align with the resistance phenotype,suggesting the possible existence of other resistance mechanisms.Pathogenicity tests showed that the isolated bacteria had strong pathogenicity,and 12 major virulence genes of Escherichia coli were detected.The study indicates that the isolated bacteria are pathogenic Escherichia coli from pheasant,exhibiting complex antibiotic resistance and strong virulence.
Pathogenic Escherichia coli of pheasantAntibiotic sensitivity testVirulence genesAntibiotic resistance genesPathogenicity test
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